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Hugh Pickens writes "An article by Ross Andersen makes note of Freeman Dyson's prediction in 1960 that every civilization in the Universe eventually runs out of energy on its home planet, a major hurdle in a civilization's evolution. Dyson argued that all those who leap over it do so in precisely the same way: they build a massive collector of starlight, a shell of solar panels to surround their home star. Last month astronomers began a two-year search for Dyson Spheres, a search that will span the Milky Way, along with millions of other galaxies. The search is funded by a sizable grant from the Templeton Foundation, a philanthropic organization that funds research on the 'big questions' that face humanity, questions relating to 'human purpose and ultimate reality.' Compared with SETI, a search for Dyson Spheres assumes that the larger the civilization, the more energy it uses and the more heat it re-radiates. If Dyson Spheres exist, they promise to give off a very particular kind of heat signature, a signature that we should be able to see through our infrared telescopes. 'A Dyson Sphere would appear very bright in the mid-infrared,' says project leader Jason Wright. 'Just like your body, which is invisible in the dark, but shines brightly in mid-infrared goggles.' A civilization that built a Dyson Sphere would have to go to great lengths to avoid detection, building massive radiators that give off heat so cool it would be undetectable, a solution that would involve building a sphere that was a hundred times larger than necessary. 'If a civilization wants to hide, it's certainly possible to hide,' says Wright, 'but it requires massive amounts of deliberate engineering across an entire civilization.'"

It also assumes that there aren't any energy advancements that are so far out of our understanding right now that they wouldn't seem like magic if we possessed them. Our assumptions are limited by our current understanding. In the next thousand years we could see all kinds of advancements that render building a Dyson sphere completely unnecessary.

It also assumes that there aren't any energy advancements that are so far out of our understanding right now that they wouldn't seem like magic

Which is a reasonable assumption. Advanced civilizations will certainly have more advanced technology, but basic laws of reality will still apply. There is no reason to believe that the second law of thermodynamics can be violated, and overwhelming evidence that it cannot.

Basic laws of reality? Isn't science about increasing our understanding of reality? Many theories and ideas have come and gone and been replaced by more refined ones. We would be extremely naive to think our current understanding is even remotely close to all there is to know and completely correct. There is much to learn my friend.

Indeed. Shakespeare said it first: "there are more things in heaven and earth than exist in your philosophy." Science is just how we're trained to look at reality, It doesn't explain love or spirituality. How does science explain psychics? Auras, the afterlife, the power of prayer?

For those who don't get the reference it's a beat poem called Storm by Tim Minchinhttp://www.youtube.com/watch?v=HhGuXCuDb1U [youtube.com]He's very much being derisive of that sort of viewpoint.Sorry to spoil the joke.

And don't get me started on Santa Claus. How does he deliver toys to over a billion homes in one night? Science offers no plausible explanation for that.

Relative velocity time dilation has been understood for years. Please leave your geek card at the door on the way out.

Reltive velocity time dilation only theoretically solves the time aspect of the problem, and only if you neglect the fact that at least the delivered presents have to STOP in my frame of reference..

I don't care how damn amazing a Wii U is supposed to be, when 1.5 kg of mass rips to a halt under my Christmas tree from, let's be generous here, 0.9c, the resulting vaporization of my house (k.e. ~ 0.5mv^2, or 1.09*10^17 joules, or 26.06 Mt of TNT) is going to result in a very unhappy Christmas.

So? From the viewpoint of someone standing still, he can still not move faster then the speed of light. And any time he drops off a toy, he has to either slow down slowly, or subject the toy itself to extreme g forces. Since toys arrive in a non-squished condition (and they are generally not resistant to high g, as the kids soon discover), then Santa has to slow them down slowly - taking quite a bit of time for every toy dropped off.

Each toy is delivered with the elf who made it.The elf slows the toy down on descent, places it neatly, and promptly burns itself to death in the fire place. If you don't have a fireplace the elf will flush itself, use the garbage disposal, provoke the dog into eating it, or, failing all of those, walk outside and freeze to death. Most people confuse their bodies for garden gnomes.

If you mean Auroras, we've got you covered. If you mean the fuzzy, ill defined fields that come up when you overexpose film or electronic sensors, well, we've got that covered as well.

the afterlife

What afterlife? Before it needs explaining, it needs existing.

the power of prayer?

What "power of prayer"? The non existent causal relationship between other people praying for someone and having an outcomes change? That doesn't happen. The ability of the plastic human mind to influence the rest of the body (to which it's intimately connected)? May I introduce you to the concept of neurobiology in all it's complexity and splendor?

The "power of prayer" goes not only against science, it even goes against true faith. If god is all-knowing and good, then he must know what is best for the people even without the people praying for it. If he needs to be told what to do, he's not all-knowing. If he does the good only if someone prays for it, he's not good. And if he does something which is not good because someone prays for it, he's even less good. Therefore we find that an all-knowing and good god cannot be influenced by prayers, and therefore the believe that prayers have objective effects (other than the normal psychological effects) shows a lack of faith.

You build a box and try to fit God inside it. When he doesn't fit, you conclude he doesn't exist. The irony is that God created the one who created the box in which God does not fit. I find that you are not even aware of your own presuppositions, therefore you cannot reach a reasonable conclusion. You have been so heavily influenced by atheists and scientism (which is practically worshipped as a religion unto itself) that you have confined your own thinking to a box which you are unwilling to exit, and perhaps even unaware of.

1. You presuppose that if God acts on a prayer, it indicates that he was previously unaware of something.2. You presuppose that if God is all-knowing and good that he must necessarily enforce what is best for people.3. You presuppose that, as a finite, relatively insignificant human being, you could possibly know whether and when God intercedes in our world and to what ends.4. You presuppose that you could even know what is "good" or "best" from the perspective of an all-knowing, all-powerful, universe-creating, life-breathing entity beyond our comprehension.

Your conclusion ("Therefore we find that an all-knowing and good god cannot be influenced by prayers...") is a non sequitur. It's not even a logical conclusion from your assertions. And your assertions are unsubstantiated, anyway.

The very nature of an omnipotent, omniscient entity who exists outside of our plane of existence means that we cannot completely comprehend him; we may only do so to the extent he chooses to reveal himself to us. What you have done is set forth arbitrary specifications for God, and if it seems to you that he does not meet your criteria, you conclude that he must not exist. This is nothing short of absurd. If God exists outside of or above our universe, if he created you and the universe and the very nature of our existence, how could you possibly define the means by which he may exist?

N.B. I am not even arguing that God does exist--I'm simply arguing that your logic is fundamentally flawed because of your presuppositions. Either God is an all-powerful, all-knowing entity--and therefore beyond our comprehension--or he is finite, like us, but with advanced technology--and therefore, presumably, ultimately understandable--or he does not exist at all. If you are arguing based on the presupposition that he is all-powerful and all-knowing, then you must argue that he is far beyond any of your reasoning or standards, and therefore you cannot logically define criteria for proving his existence.

The argument boils down to whether anything can exist beyond our understanding or comprehension: if we can comprehend God, then nothing is ultimately beyond our understanding, and--eventually, perhaps far beyond our lifetimes--we can "find" him, understand him, and even possess similar powers (note that this implies being able to create an entire universe of our own, from nothing). In this case, it's simply a matter of time until he is "discovered"--until then, he either does not exist or we have yet to find him (a conclusion which does not answer the questions, "How?", "Why?", and "From what?"). But on the other hand, if things may exist beyond our understanding, then we can never expect to meet God on our terms, and trying to do so is naive and futile.

I like the fishbowl analogy. (It's not perfect, of course.) The fish's entire universe is inside his fishbowl. He knows nothing outside of it (perhaps it would be useful to declare the fishbowl to be opaque, or at least barely translucent). Now and then something from outside his universe seems to interact with his world--perhaps a hand reaches in, but he cannot discern the source of the hand. The fish cannot comprehend existence outside of his bowl, or outside of water, the very fabric of his existence. Therefore, to him, nothing must exist outside of his world, and nothing must exist outside of water--which, to him, isn't even water, just reality as he knows it. But to the human, clearly the fish is limited

You did not read the post before asking gottabeme to read yours. The post began with an illustration of assumptions being made, then listed your assumptions.

If I pray for something and it does not happen, that does not mean my prayers were not answered. Or if I think about something without praying and my non-prayer does not appear to be answered, that does not mean it wasn't. My prayer, combined with that of others, may result in a situation in which it is not obvious to me that my prayer, or non-prayer, was even considered.

A kid finds a lamp, rubs it to shine it up a bit, and out pops the Genie.The genie grants him one wish.The kid says "I want to be Batman." So the Genie kills the kid's parents.

Was his request granted, and does the kid see that his request was granted?

We don't have the first clue what an alien civilization might do. We may have found one which is desperately trying to communicate with us but we just don't know it. We have a thought experiment by Dyson which is attempting to solve the problem by extrapolating from a string of assumptions which statistically speaking are probably increasingly invalid. The same flaw you made in your post. We may never find aliens, because they may not want to be found, and we almost certainly will never find God because he requires faith, not proof.

Hhhhmmm, After life there is what? Decomposition? Tea and crumpets with St. Peter?

The power of prayer? Seeing as the Amygdala is the part of the brain doing the heavy lifting during a prayer, let's say the power of a prayer is 15-45 microwatts depending on how hard you pray and whether you are concentrating.

I know I'm being sarcastic, but you just said it yourself, Science doesn't dabble in unreality. That would be the realm of mystics and metaphysicists. I'm not even saying none of these thing may exist. I'm saying that until you can separate the magical thinking from some describable real world phenomenon, there's nothing for science to do, but nod its head and thank you for sharing.

Sorry, but while chemistry is involved, it isn't even approximately the same as love.

It's a subset. The chemicals would be the building blocks. Like how the elements of a turning complete language (if, loop, set) are the building blocks that compose the most advance artificial intelligence system. So AI is a subset of software. Likewise love is a subset of chemistry.
There's all sorts of subjects that are tied into software that pertain to AI, like documentation, feedback loops, unit testing, etc. And there are all sorts of subjects that are tied into chemistry that pertain to love: biology, neuroscience, sociology, porn.

So rather than saying computation requires an abacus, you should be saying computation requires math. Which it does.

If I were to say that love is nothing but a bunch of chemicals bumping around, it would be perfectly true.
The economy is nothing but a bunch of wealth shuffling about.
AI programs are nothing but a bunch of bits being flipped.

This view is pertinent here because the woo-woo crowd is trying to claim that there's some mystical magical additional force/quality/aspect to it which is beyond our ken. There is not. It really does boil down to something that simple.

As far as we can tell, no macro-level system can violate thermodynamics, so the postulate should hold true. There should be IR energy given off anywhere energy is consumed as IR is the end result of an system that is not 100% efficient.

The real question is, what is the lowest level of energy difference that can be profitably collected. When you decide that, you've decided on the band of em-radiation that will be radiated. I'm not convinced that we can yet say what that would be, so it's possible that we should be looking for radio-waves. OTOH, mid-low infrared is certainly plausible. (Even if you *could* collect a tiny bit more, you've already extracted most of the energy, and building the collector would require a LOT of work. But i

Well, the second law is more of a statistical observational law than one deduced from higher principles. Its really good at predicting things and seems really reliable and is tied into all kinds of other areas of physics. I would be shocked to near death if we found a repetable, observable violation.

But the science fiction lover in me would prefer to think of it a just a setting in the universe that could be switched off when convineint. Its also linked to time, so if we can just step out of the stream of time then we're good and possibly gods.

If I've read my recent physics correctly, 95% of the energy in our universe is in a form we don't know much about (dark matter/energy). If a sufficiently advanced civilization could harness that, they are likely going to do something to target that, instead of star light.

Past performance is not an indicator of future performance. Humans always used horses... until they invented a car. Humans were using only land transport.. until they invented an airplane. Humans were always planet-bound, until they flew into space.

A Dyson sphere is not a scientific fact, it's only a possibility, and not trivial one at that. The approach has many problems.

First, the Dyson Sphere, even if it is ideally constructed, will only supply energy to your sites near the star. However it is logical to expect that an advanced civilization will need spaceships for all kinds of purposes, from research to migration. This cannot be done without movable sources of energy (thermonuclear at the least.) Once you have them, the effort of building the Dyson sphere appears to be too high.

Then the Dyson sphere needs to be constructed. There isn't much material in an average planetary system to do that, unless you can transmute your common silicon and carbon into scrith and make a thin foil out of it. You also need to deliver that material to where it is needed, and join it. A Ringworld is a much easier possibility at this point.

Once you build the sphere you need to equip it with collectors of solar energy. Where would they come from? If we build a sphere at 1AU from the Sun, do you think we can line it with solar panels? We'd have not one atom left in this Solar system after we built the sphere. Besides, the sheer volume of the effort would be impossible.

The sphere would need to be thermally balanced. (This is how they intend to find it.) If you collect all the energy and keep it inside it will heat up to the temperature of the star - and that is perhaps not what you want. So you need to cool it. Earth is rotating, radiating heat every night and collecting it every day. Planets like Mercury show what happens when a planet is thermally overloaded. The Dyson sphere would have to have radiators of energy somewhere on the external side, and there would have to be conduits. This is a lot of work.

Then the question would arise of atmosphere. Is your Dyson sphere is at 1AU then you need to live on that sphere - and that means that you must have means of holding the atmosphere in place. If you leave Earth (for example) in place and instead build the sphere on a farther orbit then the surface of your sphere grows and you need even more material. Also the problem of transportation of collected energy arises.

Considering these and other technological and conceptual difficulties, it may be easier to just use local sources of energy, like thermonuclear reactors or better. Astronomers, of course, want something to look at, and you can't look for reactors that far away. I don't think they will find Dyson spheres, though. A civilization that is advanced enough to build such a sphere probably does not need it.

Past performance is not an indicator of future performance. Humans always used horses... until they invented a car. Humans were using only land transport.. until they invented an airplane. Humans were always planet-bound, until they flew into space.

In the midst of ALL of that (horses, cars, planes, spaceships) they have all been powered (as well as the humans in them) indirectly (by about 2 or 3 steps of conversion) by the sun... Sure things change, but given how different humanity of 2012 looks compared to that of only 1000 years ago, and still it's entirely thanks to the sun, is a pretty clear suggestion that humanity will rely on the sun from now until the end of our existence. There's just too much energy shooting out of it in every direction for it to be ignored, barring something that literally violates the laws of physics as they are currently understood.

I can't recall who said it but someone (more famous than myself) put the idea out there that if you had the resources to build a Dyson sphere you wouldn't need to build one. Makes sense to me but I'm not an engineer.

It's not the issue of energy generation, but energy consumption. 100% efficient systems are theoretically impossible based on our current knowledge. If it's not 100% efficient, expect IR to be released at some point.

There's the/civilization's/ recognition of the limit, vs. the individual's desire to procreate, in the battle of need vs. freedom/rights.I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

Also, as for remaining hidden, a race may decide instead of building a Dyson sphere which radiates over it's whole surface, to instead radiate over a smaller portion of the surface, and at a narrower angle. While you could be detected from the right angle, if you point it the right way, the closest thing that could bother you, probably wouldn't be close enough to care about.

Then again, the amount of mass needed for a Dyson sphere would be insane, if you have that level of tech, to acquire that mass, you probably have other solutions to the problem (direct matter->energy conversion perhaps?)

There's the/civilization's/ recognition of the limit, vs. the individual's desire to procreate, in the battle of need vs. freedom/rights.I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

Humanity has done no such thing. Certain societies have lead to overpopulation of particular regions of our planet. Have you ever heard of the concept that you are responsible to your fellow man but not "for" them? You cannot take responsibility for the actions of others. Humanity is single homogeneous society.

You and like minded people in the "west" are doing our species more harm than good by limiting your choices and contributions to the human gene pool based on the irresponsible actions of other nations

I recognize that humanity has overpopulated the earth, that does not diminish my desire to have a child at some point.

It may not diminish your desire, but hopefully it alters your actions. At the very least I would hope you would choose have 1 or 2 and not 3 or more. If all couples had just 1 child the population would drop by 50% each generation (obviously with a time delay since people live much longer than one generation). 2 is steady state.

You'd be surprised how many people simply don't ever procreate. Your point is still valid, but if everyone who wanted/could have kids did have just 2 that lived to maturity (another factor) the population would still decline. Three kids (during your child bearing years) per willing/able couple is more practical for holding a steady population. A guilt trip for having 3 kids is completely unwarranted.

Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth,

No, he didn't assume that all civilizations would take this path, just some of them. The Universe should contain billions of civilizations. If even a tiny fraction of them build Dyson Spheres, then this search may find something.

Alien civilizations are likely products of the same kind of Darwinian process that produced humans, so the desire to expand and grow will be innate, because species which lack that desire are replaced by those that possess it.

Bees, ants, wasps, and nearly all other social insects are also adapted to living with a gender-bending endo-parasite.

Namely, the wolbachia parasite. It is a protozoan that inhabits cellular cytoplasm of the cells of those species of insects, and procreates through forcing males to develop as females, because it can only perptuate itself through the larger ova of those species, and not through the smaller sperm of those species.

As such, the centralized reproductive practice of those organisms is directly tied to the limitations imposed upon them by the highly aggressive wolbachia parasite.

Removal of the parasite through aggressive use of antibiotics has shown radical changes in cytoplasmic composition and embryonic development, which results in sexual infertility and even outright death in many infected species.

What I a getting at here is that the existence of communal reproduction centric organisms like bees and wasps does not negate the validity of the prior poster's statement, because the bees and wasps did not develop this strategy so much as have it impose upon them by a more aggressive species that does conserve the poster's conjecture.

I don't believe this. I think the most advanced aliens have probably realized that there isn't much point of growth after a certain threshold.

It's funny how these armchair physicists who got their education from bad science fiction are so adamant that we can't possibly know what magical technology we might invent that will get us around the laws of thermodynamics, so capturing starlight is crude and stupid and this project is obviously a waste of time.

But boy do they sure know the motivations of future humanity, the path of technological and societal growth, and the psychology of hypothetical aliens, and that knowledge also tells them that this project is a waste of time.

<quote>Dyson assumed that all alien civilizations are stupid enough to believe in infinite growth....</quote>

I don't know anything about Dyson, but based on our "civilization" we don't "believe" in infinite growth... we just grow to point where our growth is no longer sustainable. There is no belief or consciousness involved. Sure you you may have individuals warning about the "tipping point" of the world the civilization lives in... but until the tipping point is reached there is little the civilization can do to stop its growth. That's life in general. Every population grows until it can't. When it's over populated it shrinks. When no resources can be consumed, it dies. Populations growth will always be towards equilibrium with what-ever its surrounding can support.

If a population is advanced enough to build a a dyson sphere, and a dyson sphere is the only way to survive, then a dyson sphere will be built or the population will decrease towards 0 until the population stabilizes (which very well may be at "0").

But regardless there is no belief here. There is no concerted attempt to grow infinitely. Just ask a deer or fruit-fly. They have no clue what you're asking...but their population will certainly increase when it can and decrease when it has to.

the earth compared to the sun is like a grain of sand to a beachball. where would you get enough matter to build something around a star if the same or similar size ratio will exist in other star systems?

The energy output of a star is going to be many orders of magnitude higher than what you'd get from fusion technology. The sun is a giant fusion plant itself! A sufficiently advanced technological civilisation may very well find itself bound only by the amount of energy it could produce or harness, and getting every last scrap of energy from a star is a massive boost to an energy based economy.

Although a star has a large net output, it's only because it's so big. Proton-proton fusion has a very low energy density. Though barely conceivable by today's technology, you could theoretically produce the Sun's output in a powerplant a few km across going to D-D or P-11B fusion fuel. No stars are therefore necessary. Matter-antimatter reactions would be orders of magnitude better still.

Matter-antimatter reactions may have extremely high power density, but there's a big problem: where do you get the antimatter from? It's unlikely there's large naturally-occurring deposits of it available anywhere, since it annihilates itself when it contacts matter. M-A energy sources really only make sense as a way of storing energy, not producing it. Even Star Trek takes this position: the starships use antimatter for propulsion, but only because of the energy/power density it offers, and it's produced artificially specifically for this purpose, probably using solar energy production.

Energy is a primary need of any civilization. Every civilization has to get it somewhere. Back in the early days, we got our energy from the sun solely: we used it to grow crops (for food) and feed our animals (for transportation), and to power our ships (for water-based transportation; we used the sun to produce wind to power these ships; luckily, we didn't have to produce the wind ourselves, as natural processes had already done this for us, but we took advantage of it). These days, we largely get our energy from hydrocarbons created millions of years ago by solar-fueled processes, though we're getting some power from nuclear fission (where we break apart large atoms that were created in stars long ago). In short, we get energy where we can find it naturally-occurring. A more advanced civilization will probably be no different: though it may convert energy from one form to another, it'll have to mine that energy from somewhere, and the most obvious source is a nearby star which is giving off lots of energy for free already. Of course, if they figure out how to get energy directly from quantum fluctuations, or by mining antimatter from a parallel universe or something, then they might not need stars any more, but that sounds even more advanced than a Kardashev Class II civilization which we're talking about here.

I've read about Dyson Sphere's being equipped with stellar engines. Basically, it's now a giant starship (in the true meaning of the word) built around a core source of power. A star.

If you though taking an international flight from halfway around the world was a bitch, imagine taking a trip from one side of the starship to the other. Perhaps they will have the whole teleportation thing figured out by then.

A star is a fusion reactor. In fact, if you need the kind of power that's given out by a Dyson sphere, then a Dyson sphere is by and large the most efficient method for generating it, especially for long periods of time.

The question should be whether any civilization would require so much power in such a static and concentrated way (as opposed to dispersed across hundreds of planets across thousands of lightyears), and where they'd find the materials required to build it (we're speaking about transforming entire planets from crust to core, or harvesting dozens more in a less destructive fashion).

Constructing a massive shell of computing substrate around a star to contain the uploaded consciousnesses of a whole civilization might be a very good reason to have a static fusion plant at the center. Such a shell could make an efficient use of what solar energy it gets in its local area without having to transmit that energy to other sections of the shell. You just have to make sure that the individuals do not clump in a small area or if they do, they clump infrequently in a a relatively few zones whi

If you're completely ignorant about a subject, is it too much to ask that you remedy the situation before farting an opinion? There are four links in the post for your education!

I mean, sure, the Templeton Foundation are a bunch of religious loons, but do you actually think you know better than Freeman Dyson and the actual physicists, astronomers, and engineers who consider the idea plausible? If so, you'd better tell them why it can't work, before they waste all that money! Your paper on the subject will make you famous!

Actually I'd argue that if you have the tech to build a Dyson sphere you've the technology to dismantle the star and make much more efficient use of the matter than merely burning it to helium.You'd want to dismantle the star and use it as a matter source for fuel and construction, the alternative is to leave it wastefully burning and then eventually exploding. What a waste when there's all that entropy there that can be used.

There really is no way to build a 0.35mm steel plate in space for more than 500 miles without it collapsing into a rubble pile.

Dyson was well aware of that. A Dyson Sphere [wikipedia.org] is not a connected solid sphere. It can consist of billions or trillions of independently orbiting structures, such as O'Neill Cylinders [wikipedia.org].

A solid structure would be a Ringworld [wikipedia.org], which is impossible to construct with our current understanding of reality.

Probably, but the issue is whether it's worth looking. If there was a detectable civilization in our range, and it later was discovered that we could have detected it much earlier via a relatively small expenditure, we'd be kicking ourselves in the ass.

Plus, it may lead to the discovery of a new unexpected natural phenomenon.

Perhaps. You seem to be making an assumption that many naysayers make, that is we've made a huge effort in detecting exo-planetary intelligence and come up with nothing. Let me add that our efforts so far have been miniscule when campared to the real relative distances involved in the search. Meaning that a real search effort with the given technology may be a bit beyond our current economic and technical ability.

Experiments don't have to be "successful" to have an impact. Michelson and Morley [wikipedia.org] failed to detect ether, yet their failed experiment revolutionized physics.

If the search finds nothing, does that mean the Rare Earth Hypothesis [wikipedia.org] is correct? Or maybe advanced civilizations find a way to hide their energy consumption, or maybe they don't grow or don't need the levels of energy that we think they do. A null result from this search leads to many interesting questions.

We build taller and taller skyscrapers. Why? There are more efficient structures, and it's not like they are there to harvest resources unavailable at ground level. Besides, some peasant can build a mountainside hut that is at a higher altitude than the highest skyscraper. So, maybe it's not about the energy. Maybe it's a statement of prowess, or art.

Small black holes are basically 100% efficient at turning mass into energy via Hawking Radiation, which is nearly two orders of magnitude more efficient than Stars powered by fusion.

There are some serious suggestions as to how to go about making them (ultra powerful converging gamma ray lasers, as photons aren't subject to Pauli Exclusion Principle). While it probably requires a moon-sized machine to do it, it is probably feasible for a civilisation capable of building a Dyson sphere, and once you have tha

I was watching that Riddick movie with the Necromongers the other day and I realized that the concept was actually very realistic. What kind of society would get into space first? The ones that put a high priority on space exploration. And what kind of civilization would do that just for the heck of it before any others? The ones that have some irrational reason to do it driven by some kind of religious fervor. While the "Star Trek like" science-driven societies pace themselves in a sensible manner, the religious nutjobs would throw every single resource their entire civilization could at getting into space to please their space deity or whatever. If there's an advanced space-faring race out there you probably want to steer clear of them.

That's only given all civilizations started at roughly the same time. However, this isn't Civilization V. A space-faring race could have formed a contigous civilization several hundred thousands or millions of years ago, not a couple thousand years like ours. It might be the natural evolution of things at that point.

Actually, chances are that not only civilizations started and finished at different times, but also that

Assuming current predictors of life-supporting planets are at least within ballpark, each space-faring civilization existed, prospered and dyed off before running into any other civilization.

What more reasonable assumption is that WE are product of such advanced civilization, that is some form of life-seeding DNA-based life that originated on some planet elsewhere produced advanced civilization and they realized that due to scale of our universe they will never get to explore most of it and just seeded universe with life.

Yeah, that makes sense, until you look at reality. The European drive to colonize paid a lot of lip service to religion, but in the end it was the almighty gold piece that drove the conquest. How do we justify the cost of putting a person on the moon? By the economic benefits of the scientific discoveries and the resulting technology created.

While the "Star Trek like" science-driven societies pace themselves in a sensible manner, the religious nutjobs would throw every single resource their entire civilization could at getting into space to please their space deity or whatever. If there's an advanced space-faring race out there you probably want to steer clear of them.

What makes you think "Star Trek like" societies are science-driven? Remember the Enterprise, in all its incarnations, is a military vessel.

One of the revolutionary aspects of TOS is the purely scientific nature of their mission--they're not looking for a new home, they're not on the run from the law or some other force, they're out there just to see what's out there. But they (the crew from TOS and most every recurring character from all the other series) are members of the military.

If Dyson Spheres exist, they promise to give off a very particular kind of heat signature, a signature that we should be able to see through our infrared telescopes. 'A Dyson Sphere would appear very bright in the mid-infrared,' says project leader Jason Wright.

Right, because there's no way a civilization advanced enough to build 282743338860000000 square kilometers of solar panels is going to be able to build solar panels capable of absorbing and using mid-infrared light (heat). If the supposition is that they inevitably build Dyson spheres to capture all of the available energy coming off their star, why would they let a whole bunch of it escape as heat?

Seems like a giant waste of time and money, but I suppose they will be generating useful data while they look. Still, their chances of finding one are likely ludicrously close to zero even if one does exist. I also find the whole premise to be rather poorly thought out, I have to admit; even if a civilization is capable of building a Dyson sphere, I'm not sure it makes any sense to actually do it.

The Templeton Foundation [wikipedia.org]
that funded this research is often highly criticized for religious bias. It's kind of like oil companies providing money for research. It might be good in that it provides research funding but there's always a worry that the money from an organization with a particular point of view might skew the science.

I'm not saying that this invalidates the research, but it does cast some doubt on it and the reasons it is being done.

Ok so somehow you get enough materials and energy to shape it into a sphere. That's an impossible task, but then it's somehow even more impossible that they use radiators to disperse the heat? I mean when you're talking about impossibility, it doesn't matter if it's squared or cubed. Then once you have this shell of solar collectors, how do you get the energy inside of it? You basically have a Faraday cage.

Also, why the fuck? Any significantly advanced civilization would use gravitational engines. That is either under direct or natural control, they would set up a oscillation system between multiple orbiting bodies where they can harvest energy without needing fusion. Instead of lighting up the solar system, they'd go invisible, detectible only via gravity waves which to date, are impossible to detect. At a minimum, significantly harder to detect.

First off a dyson sphere does not take into account the MASSIVE amount of praticle energy that is coming off the star. the Stellar wind on that scale would be immense. Secondly, Orbits are not magical. a dyson sphere is unstable and will either wobble and start to collapse into the star, or rip apart due to the uneven gravity well. Just the technology to even be able to have the ability to think of building a Ringworld, something far, far, FAR easier than a Dyson sphere is so mind bogglingly compex that it collapses in upon it's self.

Sorry but it's a waste of time we might as well look for civilizations that are harvesting black holes to power their space ships.

Quick! Let's build a giant IR emitter w/ some filters to produce the same spectral curve as a Dyson sphere. All those not-quite-advanced societies out there will detect it and run screaming from our perceived galactic-overlordishness.

I don't understand this nonsense of astronomers searching the galaxy for Dyson Spheres. I had no trouble finding and buying one off Amazon. The design is revolutionary, and it's very powerful. It gets pet hairs out of my carpet with ease. Highly recommended!

Once you have self-replicating, "intelligent" machines to do the job?Assuming you could keep them interested in building your sphere, of course!

You just create your first self-replicating solar-powered Dyson-sphere builder, and then sit back and watch it and its scions build for the next hundred million years or whatever. Or maybe nowhere near that long, assuming exponential growth (to some limit) of the builder-bots.

A ringworld is a lot easier to build than a Dyson Sphere, you could do it with the material from one solar system. And you can spin it for gravity.For a dydson sphere you need to invent some sort of artificial gravity (even a sphere made of a thin layer of neutronium isnt going to work

Books to read:Orbitsville , Orbitsville Deoarture by Bob Shaw

Ringworkd , Ringworld Engineers, Ringworld Throne by Larry Niven

Anyway a Dyson Sphere is an example of a type 2 civilization (one that utilizes the entire resources of its starA type 1 civilization utilizes the entire resources of its planet and we have only scratched the surface of this one - just think how many zigawatt millenia of energy lies in the molten rock just a hundred km below your feet and all the way to the core

Further, in the traditionally-envisioned model of the Dyson Sphere (hollow sphere around a star; not Dyson's actual theory), the livable surface area of the sphere would come out to something on the order of millions of Earth-sized planets. Population control at that scale, for a society with that kind of capability, is essentially a non-issue for any reasonable length of time.

Wouldn't planet-based solar be far more affordable and efficient, and produce more than enough energy for a planet with population controlled at a reasonable level, which should be expected from any advanced civilization? Seems like it would be unlikely for an advanced civilization to build one of these given the other options (including fusion power)...

Define "reasonable level." You'll find it depends entirely on your resources. If you build a Dyson sphere, your available power resources are vastly greater (physical material such as food and water can, theoretically, by recycled with 100% efficiency given sufficient power). And it greatly benefits a society to have a larger population: faster evolution, more smart people to make advances, more culture and art are produced, and a vastly greater chance to survive any catastrophe.

I think you are 100% correct, but it's not just politicians who are small minded. Here's an example. I work in IT as a Linux System Administrator. One of my colleagues is not only extremely smart and one of the most knowledgeable IT guys I've ever worked with (he is like a living set of man pages), he is into sci fi. He feels very strongly that we have more pressing needs at home in the USA than to spend almost any money on NASA. I mean, he is the exact kind of guy who I would expect to be in favor of building a moon base. When guys like him won't even back NASA, there's really no hope for the USA to ever do anything useful in space in our lifetime unless it becomes a national security concern. But in direct response to your suggestion, I want to see a moon base first and a manned expedition to Mars before we try something massive like this. It's a "walk before you run" kind of thing.

He feels very strongly that we have more pressing needs at home in the USA than to spend almost any money on NASA. I mean, he is the exact kind of guy who I would expect to be in favor of building a moon base.

And he's right. We shouldn't go to Mars because we want to brag about putting men on Mars. We should go to Mars because investing in high tech domestic industry is an excellent solution to our economic problems. It's a good reason to invest in education, it's a good reason to pay highly educated peo

I am not like your colleague, but it may be that there is a time and a place for those sorts of expenditures. I don't think you would argue that you shouldn't be building telescopes when your family is starving, so the question becomes at what point do we have to take care of our own to the exclusion of all else. I don't think that this is the time for it, but you could argue that the US may well have been in a better place to put a man on the moon, economically, in 1969 than we are now.

It probably would be profitable, in small sections. (The original 'Dyson Fleet' version.) If you have the tech to put up orbital solar at reasonable cost, it's probably profitable to put up more and more orbital solar plants as your race grows.

Not necessarily - a Matrioshka brain is constructed from (or in the same way as) a Dyson sphere, the difference being that the brain is designed to compute using the energy it collects, while a Dyson sphere is more generic - it collects the energy and you can then do what you want with it. Advanced civilizations may only use a fraction of their power supply for computing, the rest could be used for a (very literally) unimaginable range of things.

You have to release heat. The laws of thermodynamics demand it ; even if you have a fractally complex energy usage system, it has to move outwards, or it will all grind to a halt. So you'd see a large sphere at a temperature somewhere above cosmic background - how far above would depend on the efficiency of their engineering.

Of course, this presumes that advanced civilizations will simply re-radiate the left-over thermal energy, it's entirely possible that they would have close to 100% efficient systems or have a economically sensible way of storing thermal energy to re-use at a later date.

It also presumes that advanced civilizations would waste their time and resources building such a contraption, when, given the technology necessary to do so, it would be far easier to find another planet.

The level of sophistication necessary to deploy such a thing would require a level of technology where Fusion is childs play. There would be no energy shortage.

It also presumes that advanced civilizations would waste their time and resources building such a contraption, when, given the technology necessary to do so, it would be far easier to find another planet.

Would it? The technology required to build any kind of Dyson sphere and the technology required to move a large population to another star are both so far beyond our own capability that there is little basis to judge which is easiest.

Eventually, the energy is converted to heat, which can leak out into space. Our planet is not a closed system. The good thing is that there is also energy coming in into our system (solar energy, for example).

Most engineers already think a total dyson sphere is absurd, at least for a first or even 10th effort. The task of fulling enclosing a star?Instead most likely what you would see would be a network of solar arrays, mssive though they be, but also most likely out of the orbital plane ("polar" caps being the most logical and simplest logitically), so that the majority of the star's light still radiates normally.